This invention is in the field of computers. In particular, it relates to methods and apparatus for constructing computers.
Portable computers are known. A typical portable computer is comprised of two sections. The first is the display panel. The second is the computer itself, which typically comprises a small case-like structure. The case is usually formed from two separate halves, the upper half having the keyboard mounted thereon and the lower half having the logic board, the hard disk drive and the floppy disk drive mounted therein. The two halves are fastened together in a variety of ways and the display panel is fastened to the case with hinges, which allow the display to be folded down onto the case. When not in use and with its display panel folded down, a portable computer makes a very compact and easily carried unit.
Most of the cases for such computers have been constructed from two pieces of very stiff plastic or composite material. The various components, including the logic board and disk drives, are attached to either the upper or lower half of the case by means of screws or other such fastening means. Electromagnetic Interference ("EMI") protection is incorporated into the case by placing a sheet of shielding material inside both halves of the case or by surrounding the relevant components with a metal structure which isolates them from the environment.
Although these methods for constructing portable computers are acceptable, they leave room for improvement. By mounting most major components on the case itself, the computer is susceptible to either momentary or permanent failure whenever it receives a shock or vibration greater than a relatively low level. The structural stiffness available from a plastic or composite material is also typically less than that from metal. However, the weight and cost penalty for fabricating the entire case from metal is usually too great for a portable computer, except in such specialty markets as the military.
Known attempts to correct these problems include portable computers where the case is formed from die-cast metal upper and lower halves. Although this creates a very strong and durable computer, it weights too much for easy portability and the cost of such a computer is too high. Other manufactures have made various subassemblies from sheet metal but the resulting computer is not noticeably stronger.
A new method for constructing a portable computer, which would improve the structural integrity of the computer without increasing its weight or cost would be very desirable. If that method could also improve EMI protection of the finished computer, that would be even more desirable.